diff options
| -rw-r--r-- | drivers/gpio/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 188 | ||||
| -rw-r--r-- | include/linux/gpio/driver.h | 29 |
3 files changed, 220 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 2e461e459d8..51c78253268 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -55,6 +55,9 @@ config GPIO_ACPI def_bool y depends on ACPI +config GPIOLIB_IRQCHIP + bool + config DEBUG_GPIO bool "Debug GPIO calls" depends on DEBUG_KERNEL diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 584d2b465f8..f41cb4f3d71 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1254,6 +1254,9 @@ fail: } EXPORT_SYMBOL_GPL(gpiochip_add); +/* Forward-declaration */ +static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); + /** * gpiochip_remove() - unregister a gpio_chip * @chip: the chip to unregister @@ -1270,6 +1273,7 @@ int gpiochip_remove(struct gpio_chip *chip) spin_lock_irqsave(&gpio_lock, flags); + gpiochip_irqchip_remove(chip); gpiochip_remove_pin_ranges(chip); of_gpiochip_remove(chip); @@ -1339,6 +1343,190 @@ static struct gpio_chip *find_chip_by_name(const char *name) return gpiochip_find((void *)name, gpiochip_match_name); } +#ifdef CONFIG_GPIOLIB_IRQCHIP + +/* + * The following is irqchip helper code for gpiochips. + */ + +/** + * gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip + * @gpiochip: the gpiochip to add the irqchip to + * @irqchip: the irqchip to add to the gpiochip + * @parent_irq: the irq number corresponding to the parent IRQ for this + * chained irqchip + * @parent_handler: the parent interrupt handler for the accumulated IRQ + * coming out of the gpiochip + */ +void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, + struct irq_chip *irqchip, + int parent_irq, + irq_flow_handler_t parent_handler) +{ + irq_set_chained_handler(parent_irq, parent_handler); + /* + * The parent irqchip is already using the chip_data for this + * irqchip, so our callbacks simply use the handler_data. + */ + irq_set_handler_data(parent_irq, gpiochip); +} +EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip); + +/** + * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip + * @d: the irqdomain used by this irqchip + * @irq: the global irq number used by this GPIO irqchip irq + * @hwirq: the local IRQ/GPIO line offset on this gpiochip + * + * This function will set up the mapping for a certain IRQ line on a + * gpiochip by assigning the gpiochip as chip data, and using the irqchip + * stored inside the gpiochip. + */ +static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) +{ + struct gpio_chip *chip = d->host_data; + + irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler); + irq_set_chip_data(irq, chip); +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + irq_set_noprobe(irq); +#endif + irq_set_irq_type(irq, chip->irq_default_type); + + return 0; +} + +static const struct irq_domain_ops gpiochip_domain_ops = { + .map = gpiochip_irq_map, + /* Virtually all GPIO irqchips are twocell:ed */ + .xlate = irq_domain_xlate_twocell, +}; + +static int gpiochip_irq_reqres(struct irq_data *d) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(d); + + if (gpio_lock_as_irq(chip, d->hwirq)) { + chip_err(chip, + "unable to lock HW IRQ %lu for IRQ\n", + d->hwirq); + return -EINVAL; + } + return 0; +} + +static void gpiochip_irq_relres(struct irq_data *d) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(d); + + gpio_unlock_as_irq(chip, d->hwirq); +} + +static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) +{ + return irq_find_mapping(chip->irqdomain, offset); +} + +/** + * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip + * @gpiochip: the gpiochip to remove the irqchip from + * + * This is called only from gpiochip_remove() + */ +static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) +{ + if (gpiochip->irqdomain) + irq_domain_remove(gpiochip->irqdomain); + + if (gpiochip->irqchip) { + gpiochip->irqchip->irq_request_resources = NULL; + gpiochip->irqchip->irq_release_resources = NULL; + gpiochip->irqchip = NULL; + } +} + +/** + * gpiochip_irqchip_add() - adds an irqchip to a gpiochip + * @gpiochip: the gpiochip to add the irqchip to + * @irqchip: the irqchip to add to the gpiochip + * @first_irq: if not dynamically assigned, the base (first) IRQ to + * allocate gpiochip irqs from + * @handler: the irq handler to use (often a predefined irq core function) + * @type: the default type for IRQs on this irqchip + * + * This function closely associates a certain irqchip with a certain + * gpiochip, providing an irq domain to translate the local IRQs to + * global irqs in the gpiolib core, and making sure that the gpiochip + * is passed as chip data to all related functions. Driver callbacks + * need to use container_of() to get their local state containers back + * from the gpiochip passed as chip data. An irqdomain will be stored + * in the gpiochip that shall be used by the driver to handle IRQ number + * translation. The gpiochip will need to be initialized and registered + * before calling this function. + * + * This function will handle two cell:ed simple IRQs. Everything else + * need to be open coded. + */ +int gpiochip_irqchip_add(struct gpio_chip *gpiochip, + struct irq_chip *irqchip, + unsigned int first_irq, + irq_flow_handler_t handler, + unsigned int type) +{ + struct device_node *of_node; + unsigned int offset; + + if (!gpiochip || !irqchip) + return -EINVAL; + + if (!gpiochip->dev) { + pr_err("missing gpiochip .dev parent pointer\n"); + return -EINVAL; + } + of_node = gpiochip->dev->of_node; +#ifdef CONFIG_OF_GPIO + /* + * If the gpiochip has an assigned OF node this takes precendence + * FIXME: get rid of this and use gpiochip->dev->of_node everywhere + */ + if (gpiochip->of_node) + of_node = gpiochip->of_node; +#endif + gpiochip->irqchip = irqchip; + gpiochip->irq_handler = handler; + gpiochip->irq_default_type = type; + gpiochip->to_irq = gpiochip_to_irq; + gpiochip->irqdomain = irq_domain_add_simple(of_node, + gpiochip->ngpio, first_irq, + &gpiochip_domain_ops, gpiochip); + if (!gpiochip->irqdomain) { + gpiochip->irqchip = NULL; + return -EINVAL; + } + irqchip->irq_request_resources = gpiochip_irq_reqres; + irqchip->irq_release_resources = gpiochip_irq_relres; + + /* + * Prepare the mapping since the irqchip shall be orthogonal to + * any gpiochip calls. If the first_irq was zero, this is + * necessary to allocate descriptors for all IRQs. + */ + for (offset = 0; offset < gpiochip->ngpio; offset++) + irq_create_mapping(gpiochip->irqdomain, offset); + + return 0; +} +EXPORT_SYMBOL_GPL(gpiochip_irqchip_add); + +#else /* CONFIG_GPIOLIB_IRQCHIP */ + +static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {} + +#endif /* CONFIG_GPIOLIB_IRQCHIP */ + #ifdef CONFIG_PINCTRL /** diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 9fe28364225..c1c5c2368fc 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -3,6 +3,9 @@ #include <linux/types.h> #include <linux/module.h> +#include <linux/irq.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> struct device; struct gpio_desc; @@ -97,6 +100,17 @@ struct gpio_chip { bool can_sleep; bool exported; +#ifdef CONFIG_GPIOLIB_IRQCHIP + /* + * With CONFIG_GPIO_IRQCHIP we get an irqchip inside the gpiolib + * to handle IRQs for most practical cases. + */ + struct irq_chip *irqchip; + struct irq_domain *irqdomain; + irq_flow_handler_t irq_handler; + unsigned int irq_default_type; +#endif + #if defined(CONFIG_OF_GPIO) /* * If CONFIG_OF is enabled, then all GPIO controllers described in the @@ -190,6 +204,21 @@ struct gpiod_lookup_table { void gpiod_add_lookup_table(struct gpiod_lookup_table *table); +#ifdef CONFIG_GPIOLIB_IRQCHIP + +void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, + struct irq_chip *irqchip, + int parent_irq, + irq_flow_handler_t parent_handler); + +int gpiochip_irqchip_add(struct gpio_chip *gpiochip, + struct irq_chip *irqchip, + unsigned int first_irq, + irq_flow_handler_t handler, + unsigned int type); + +#endif /* CONFIG_GPIO_IRQCHIP */ + #else /* CONFIG_GPIOLIB */ static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) |